Sub Copy_Sheet()

    Dim ws As Worksheet, sName As String, num As Integer, i As Integer, x As Integer, y As Integer

    Set ws = ThisWorkbook.Worksheets(4)

    num = InputBox("How Many Sheets?")

    x = Val(Split(ws.Name, "-")(0))

    y = Val(Split(ws.Name, "-")(1))

    For i = 1 To Val(num)

        x = x + 1: y = y + 1

        sName = x & "-" & y

        If Evaluate("ISREF('" & sName & "'!A1)") Then GoTo Skipper

        ws.Copy After:=ThisWorkbook.Worksheets(ThisWorkbook.Worksheets.Count)

        ActiveSheet.Name = sName

Skipper:

    Next i

End Sub